Two-dimensional parallel acquisition system in spread spectrum communication

Abstract

The invention discloses a two-dimensional parallel acquisition system in spread spectrum communication, which comprises a detection part and a check part. A data preprocessing unit in the detection part performs down-conversion and down-sampling to signals and simultaneously performs down sampling to local codes, results are saved in a buffer memory I, then the results are transmitted to partial matching filters for computation, the results are saved in a buffer memory II, then the results are sequentially transmitted to an FFT (Fast Fourier Transform) and incoherent accumulation unit, the results are saved in a buffer memory III, finally the results are transmitted to peak searching unit for searching for a code phase a Doppler frequency offset corresponding to a maximum value, and the results are transmitted to the check part; a code time delay unit and a frequency offset compensation unit in the check part respectively perform code time delaying and signal frequency offset compensation to the detection results, the results are transmitted to an accumulation unit for coherent and incoherent accumulation, then the results are transmitted to a control unit for threshold judgment, the acquisition is successful if the results exceed a threshold, otherwise, the acquisition of a next section is performed and the acquisition is failed if all code phases are traversed. The two-dimensional parallel acquisition system in spread spectrum communication has the beneficial effects that the parallel acquisition of the code phase and the Doppler frequency offset is realized through a streamline method and the acquisition efficiency is greatly improved.

Description

Technical field [0001] The invention relates to a two-dimensional parallel acquisition system in spread spectrum communication, in particular to a two-dimensional parallel acquisition system of pseudo-code phase and Doppler frequency offset in a satellite navigation system. Background technique [0002] Current satellite navigation systems use spread spectrum technology, including my country's "Beidou-1" and "Beidou-2" satellite navigation systems. Since the acquisition performance of satellite signals directly determines the sensitivity of the receiver and the key performance of the first positioning time, the rapid acquisition of spread spectrum signals has been a hot topic in domestic and foreign research. The traditional short pseudo code acquisition method is relatively mature, and the direct acquisition calculation for the P code with long period and high rate is very large. If the traditional short pseudo code acquisition method is still used, it will take a long time to c...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to propose a two-dimensional parallel acquisition system in spread spectrum communication, realize the two-dimensional parallel acquisition of pseudo code phase and Doppler frequency deviation in satellite navigation system, thereby solving the low efficiency of traditional short pseudo code acquisition method question

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